1 files changed, 106 insertions, 0 deletions
diff --git a/src/gasp.cc b/src/gasp.cc
new file mode 100644
index 0000000..2adcc94
--- /dev/null
+++ b/src/gasp.cc
@@ -0,0 +1,106 @@
+// Copyright (c) 2009 The Chromium Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style license that can be
+// found in the LICENSE file.
+
+#include "gasp.h"
+
+// gasp - Grid-fitting And Scan-conversion Procedure
+// http://www.microsoft.com/opentype/otspec/gasp.htm
+
+#define DROP_THIS_TABLE \
+  do { delete file->gasp; file->gasp = 0; } while (0)
+
+namespace ots {
+
+bool ots_gasp_parse(OpenTypeFile *file, const uint8_t *data, size_t length) {
+  Buffer table(data, length);
+
+  OpenTypeGASP *gasp = new OpenTypeGASP;
+  file->gasp = gasp;
+
+  uint16_t num_ranges;
+  if (!table.ReadU16(&gasp->version) ||
+      !table.ReadU16(&num_ranges)) {
+    return OTS_FAILURE();
+  }
+
+  if (gasp->version > 1) {
+    // Lots of Linux fonts have bad version numbers...
+    OTS_WARNING("bad version: %u", gasp->version);
+    DROP_THIS_TABLE;
+    return true;
+  }
+
+  if (num_ranges == 0) {
+    OTS_WARNING("num_ranges is zero");
+    DROP_THIS_TABLE;
+    return true;
+  }
+
+  gasp->gasp_ranges.reserve(num_ranges);
+  for (unsigned i = 0; i < num_ranges; ++i) {
+    uint16_t max_ppem;
+    uint16_t behavior;
+    if (!table.ReadU16(&max_ppem) ||
+        !table.ReadU16(&behavior)) {
+      return OTS_FAILURE();
+    }
+    if ((i > 0) && (gasp->gasp_ranges[i - 1].first >= max_ppem)) {
+      // The records in the gaspRange[] array must be sorted in order of
+      // increasing rangeMaxPPEM value.
+      OTS_WARNING("ranges are not sorted");
+      DROP_THIS_TABLE;
+      return true;
+    }
+    if ((i == num_ranges - 1u) &&  // never underflow.
+        (max_ppem != 0xffffu)) {
+      OTS_WARNING("The last record should be 0xFFFF as a sentinel value "
+                  "for rangeMaxPPEM");
+      DROP_THIS_TABLE;
+      return true;
+    }
+
+    if (behavior >> 8) {
+      OTS_WARNING("undefined bits are used: %x", behavior);
+      // mask undefined bits.
+      behavior &= 0x000fu;
+    }
+
+    if (gasp->version == 0 && (behavior >> 2) != 0) {
+      OTS_WARNING("changed the version number to 1");
+      gasp->version = 1;
+    }
+
+    gasp->gasp_ranges.push_back(std::make_pair(max_ppem, behavior));
+  }
+
+  return true;
+}
+
+bool ots_gasp_should_serialise(OpenTypeFile *file) {
+  return file->gasp;
+}
+
+bool ots_gasp_serialise(OTSStream *out, OpenTypeFile *file) {
+  const OpenTypeGASP *gasp = file->gasp;
+
+  if (!out->WriteU16(gasp->version) ||
+      !out->WriteU16(gasp->gasp_ranges.size())) {
+    return OTS_FAILURE();
+  }
+
+  for (unsigned i = 0; i < gasp->gasp_ranges.size(); ++i) {
+    if (!out->WriteU16(gasp->gasp_ranges[i].first) ||
+        !out->WriteU16(gasp->gasp_ranges[i].second)) {
+      return OTS_FAILURE();
+    }
+  }
+
+  return true;
+}
+
+void ots_gasp_free(OpenTypeFile *file) {
+  delete file->gasp;
+}
+
+}  // namespace ots